The drones now snooping over Afghanistan have a longer history than you might think. In 1916, a military scientist conceived of an "aerial torpedo" designed to be loaded with explosives and steered into the deadly Zeppelins on their bombing raids over southern England. In a lecture to the Royal Aeronautical Society on Monday evening Michael Draper, author of Sitting Ducks & Peeping Toms, will lift the wraps off the secret century of unmanned air vehicles, starting with the prototype referred to by the innocuous initials "AT".

The fledgling air ministry's Professor Archibald Low, an eccentric scientist straight out of central casting, had never designed anything remotely aeronautical, but put together a monoplane made of wood and tin, using the lower wing from a biplane and, scrounged from another aircraft, an oversized propeller driven by a 35 horse-power engine. There was one radio control for up and down, and another for left and right.

The professor's "queer little aeroplane" was uncontrollable when demonstrated for the army and navy's top brass. It went ape, veering around on the ground and nearly wiping out the uniformed bigwigs. When it actually took off, in a 1917 test flight, it shot bravely into the air, looped the loop and crashed yards from the lorry that launched it via a pneumatic catapult.

"Low wasn't actually allowed to fly it, because he wasn't a pilot," explains Draper. The trained pilot who operated the craft had never, of course, flown anything by radio control; this may not have helped. And before long, says Draper, "the end of the war intervened". But he is certain though that, given time, the AT would have had the enemy's war balloons plummeting like lead Zeppelins. Pilotless aeroplanes were developed successfully between the wars but they droned around purely to provide target practice. It was in the second Gulf war that they really came into their own by sending live television pictures to their handlers, a development that would have baffled boffins, however far-sighted, in 1916.